Construction of projectiles



Jan 5 1955 J. l.. A. URDAPILLETA 3,164,091

CONSTRUCTION OF PROJECTILES Filed Sept. 14, 1953 2 Sheets-Sheet 1 ATTORNEY Jall- 5, 1965 J. l.. A. URDAPILLETA 3,164,091

CONSTRUCTION oF PRoJEcTrLEs 2 Sheets-Sheet 2 Filed Sept. 14, 1955 Jas-5 a/.s 4MM/6M (Jamo/lfm Bywmf/ ATTORNEY United States PatentO 3,164,091 CONSTRUCTION F PROJECTILES Jos Luis Amilibia Urdapilleta, Calle Miramar No. 4,

San Sebastian, Spain Filed Sept. 14, 1953, Ser. No. 379,780 Claims priority, application Spain Sept.

1952, 205,572 3 Claims. (Cl. 10264) i F1o. 3;

for the thrower and his comrades, due to their range being of the order of metres, Whereas their irregular fragmentation is apt to spread over an area of up to 100 metres. The application of the improvements claimed herein to this class of grenades, assures a uniform metallic fragmentation, thus limiting the radius of action of the scraps in such a manner that, upon utilizing the grenade in an offensive action, there is no danger forrthe person hurling it.

The situation varies when the improvements in accordance with the invention are applied to mortar and gun projectiles, as then there is no need to take into consideration their action on the person firing same, and only a large, but effective fragmentation is required; -that is to say, into pieces of the most efficient sizes.

The invention has essentially been designed for use in projectiles, rockets or grenades formed of thin cases or shells, apt to produce very little shot during their explosion, or for bodies of a larger thickness, that have not been supplied with potential fracture lines, and to which supplementary casings have been applied in order to assure the desired fragmentation. Thus, any of these projectiles, whose bodies are made of la thin plate, cardboard, plastic or hardened thermoplastic materials, may be fitted or encased `in an outer case or shell formed of a cast iron jacket of an appropriate thickness or else formed by winding round said body an iron retaining or reenforcing bar forming a spiral whose pitch may be equal to or larger than the diameter or thickness of the bar.

Should these jackets not be provided with potential fracture lines by a molding or machining process, they would then only produce a scant number of small shot. Therefore, in order to increase splitting and fragmentation without the need of such lines, there is inserted between the metal jacket and the projectile or grenade body, a light jacket made of a plastic or any other suitable material, upon which flutes are swaged or molded in the direction of the generatrices, or in such other directions as may be considered most advisable.

These flutes to control the degree of fragmentation may also be molded or swaged directly on the projectile body, or else on the molded block constituting the explosive charge.

The arrangements described above thereby regulate the explosive action of the surrounding assembly in such a manner as will insure an abundant 'and regular splitting and fragmentation of the metallic cases or shells.

By varying the diameter or thickness of the Wire or bar forming the iron or steel hoop, or the dimensions of the fluting, or both, it is possible to modify the mass of fragments so that the pieces or scraps assume the most suitable size for the effect sought to be obtained.

Several preferred and illustrative embodiments of the invention as applied to different forms of ordnance projectiles, grenades or rockets are shown in the accompanying drawings, wherein of FIG. 9.

' accordance with the invention;

.ment of a hand grenade; v

3,164,091 Patented Jawa-1965 FIG. lis a vertical sectional view of a handfgreadeiin FIG. 2 is a horizontal sectional view alongrlinefzjyZ FIG. 3 is a vertical sectional view of'another embodi- FIG. 4 is 'a horizontal sectional vieW along line 4,--4 of FIG. 5 is a vertical sectional View of artilleryprojectilerembodying the principle of the invention; v

FIG. 6 is a horizontal sectional view along line 6-6 of FIG. 7 is a vertical sectional view of a ysecond embodiment of an artillery shell with certain parts in elevation; FIG. k8 is a horizontal sectional View along line. Sf- S of FIG. 7;

FIG. 9 is a vertical sectional View of a third embodiment of an artillery shell with certain `parts in elevation; and y FIG. 10 is a horizontal sectional view along .linez10-10 In FIG. 1 is shown a hand grenade having a oase or housing 2 enclosing an explosive charge 4. The metallic bar 1, which may be of circular or other cross-section, is wound around the case 2, which kmay be formed of any suitable material such as metal, cardboard, plasticV or the like. The pitch of the Vspirallyformed jacket` 1 is equal to or greater than the thickness of the bar from which Vthe jacket is formed. In other words, the spacing between the individual spirals controls the pattern of fragmentation of the case 2 of the projectile and the 'explosive housed therein. l

The other structural elements of the illustrated hand grenade are not germane to the invention; the grenade may be formed of cast metal or plastic to which may be threaded an end closure in which may be inserted a detonator tube which is activated by a fuse plug mounted in one end of the grenade, the other end of the grenade being closed olf by a threaded closure.

As shown in FIGS. 1 and 2, the case 2 is provided with a plurality of longitudinally extending grooves parallel to the longitudinal axis of the grenade. The wires 1 bear upon the salient flutes formed between the grooves so that alternatively one portion of the wire is supported while the other is not. Upon explosion of the charge 4, the

spiral winding of the wire or bar, in conjunction with the` grooving of the housing, determines the potential fracture lines of the grenade so that the desired degree of fragmentation may be attained. This pattern may be modified by varying the pattern of the grooves in the case, the diameter or thickness of the wire surrounding the case and the spacing between the individual spirals of the surrounding bar.

In the case of the hand grenade shown in FIGS. 3 and 4, the spinally Wound reenforcing bar 1 is disposed between the case 2 surrounding the explosive and an external jacket 5 which may be formed of metal, cardboard or plastic. The case 2 is provided with longitudinally extending grooves, similarly to the corresponding element in the embodiment described above, which, together with the spirally wound reenforcing bar 1, controls the character and degree of fnagmentation occasioned by the explosion of the charge 4.

FIGS. 5 and 6 show an artillery projectile consisting of a metal jacket 15 capped with a detonator head, as commonly known in the art. surrounded with an externally grooved jacket 12 which in turn is surrounded by the spiral steel wire reenforcement 11 which functions in a manner similar to the spiral wire jacket 1 described in connection with the hand grenade illustrated in FIGS. 1 to 4.

In the artillery projectile shown in FIGS. 7 and 8, the

The explosive charge 14 is internal metallic case or shell 6 surrounds the explosive charge 14 and the exterior offthis case is subdividedV by a series of grooves S extending longitudinally of the axis of the case and transversely thereof to subdivide the case into predetermined sectional parts which will cause fragmentation in conformity to the size of the sections of the case between the grooves therein. The solid metal housing 1S encloses the internal subdivided case which en- Compasses the explosive charge 14.

In the artillery shell shown in FIGS. 9 and l0, the metal shell 26 encompasses a molded explosive charge 24 on the lateral surface of which has been directly molded a plunality-of grooves extending longitudinally and circumferentially of the explosive body in order to develop potential fragmentation lines in the assembly.

The expedients shown in the several different embodiments of the invention may be applied to the others, for example, a molded explosive charge with potential fragmentation lines formed therein by a plurality of angularly disposed grooves may be applied as Well to a hand grenade of the type shown in FIGS. l to 4 as to an artillery shell as shown in FIGS. 9 and l0.

While l have described my invention as embodied in a specic form and as operating in a specific manner for purposes of illustration, it should be understood that I do not limit my invention thereto, since various modifications will suggest themselves to those Skilled in the art without departing from the spirit of my invention, the scope of which is set forth in the annexed claims,

I claim:

1. An explosive projectile comprising an explosive charge, a housing for said charge including a cylindrical portion having a longitudinal axis of revolution and having groo 'es on its exterior extending in parallel to said axis of revolution of said cylindrical portion of said projectile, a wire loop formed of a plurality of spaced turns of tially transversely to said grooves, and an additional externial casing surrounding said Wire loop.

2. A hand grenade comprising an explosive charge and an external housing therefor, said housing comprising spaced walls at least theinner one of which is provided with grooves therein, and a metal bar wound spirally between said Walls transversely to said grooves and surrounding said explosivecharge to deine therewith a predetermined pattern o fragmentation.

3. An artillery shell comprising an explosive charge and a confining case therefor including a cylindrical portion and a conical tip having a longitudinal axis of revolution, grooves on said case parallel to said longitudinal axis of revolution of said shell, a metallic wire loop formed of a plurality of spaced turns of wire wound spirally around the cylindrical portion of said case and substantially transversely to said grooves, and an iron jacket enclosing said explosive charge, com'ining case and wire loop.

References Cited by the Examiner UNITED STATES PATENTS 90,164 5/69 Gibson 102-67 1,015,944 l/l2 Du Pont 102-67 1,203,062 l0/l6 Semple 102-64 1,276,082 8/18 Kuhn 102-67 2,007,026 7/35 Robertson 102-67 2,023,158 12/35 Williams 102-64 2,299,904 10/42 Keeling 102-64 2,382,277 8/45 Whitesell 102-67 XR 2,385,398 9/45 Blum 102-64 BENJAMIN A. BORCHELT, Primary Examiner.

SAMUEL BOYD, Examiner. 

2. A HAND GRENADE COMPRISING AN EXPLOSIVE CHARGE AND AN EXTERNAL HOUSING THEREFOR, SAID HOUSING COMPRISING SPACED WALLS AT LEAST THE INNER ONE OF WHICH IS PROVIDED WITH GROOVES THEREIN, AND A METAL BAR WOUND SPIRALLY BETWEEN SAID WALLS TRANSVERSELY TO SAID GROOVES AND SURROUNDING SAID EXPLOSIVE CHARGE TO DEFINE THEREWITH A PREDETERMINED PATTERN OF FRAGMENTATION. 